Piston pump



E. BOBARD PISTON PUMP Aug. 15, 1950 2 Sheets-Sheet 1 Filed Aug. 6. 1946N DUE/77 0f Znw/cB Aqrq E. BOBARD PISTON PUMP Aug. 15, 1950 2Sheets-Sheet 2 [harem/or 5071/63 50 bare Patented Aug. 15, 1950Emileiflobard .eann,.Etenee:

A sgSt 6, 6.;S'e .h Frhnee' Augujsfjgog is lai ns-w (Quasi-1:10

invention has for its; oftject imprdi/emnts,

ini piston pumps: bperate'd;v by at rotary" shaft; with a view toreducing their: weight and their bulk and to/ allow for instance theirmountihg inside the rim of a pneumatic tire, the rotationvof said wheel:pro'vittihg; inthis;parse-fortthe driving of the pump- The accompanyingdrawing illustrates in. two examples the principle: my'hwntion.

Figs. 1 and. 2: are eross'i-sections respective through linelerl'ofli'ig'. Zahdthibngln Iih'e: ofsrEig; 1 off themxmp 'considere'dhas a;whole Figs 3: and 4; show: another form; of thei -invenre. tion with the'disjoonnec'ting mechanism two; diffierentpperatin'g postitions'pas in,thexdireee tionofthe arrow ofLEig'. 2;

The: -'pum p i'llustiatteclzizx-E'igs;v anda=2i includes: chiefly twocylinders l and l inside which-may reciprocate tlwo; pistons 2: and 2;"by vthe two: rods 3.- andJB' -W According; toa thine; iheven ti'on the.reciprocating 'moxriemeri't on thesepisto'ns controlled bya shaft-BJai'r'anged: -inside theagrmipi of members formed: by therc'ylinders;l= and. 11 the: flap: valve box 6, the'piston rods; 3e and 3., and theletters 8;!" serving: for; theeontmll at said: rods. T this purpose:the; shaft Smames. a. 0am I with. Whieh cooperate? the rollers 8 and 8caxrriedvhy: the/levers; 9 and; 91' pivotaliy-seclinediait t0; and, 151"to: the. rods '3; anda '3 ofthe pistons-T These: levers are: bent; forthe neason disclosed hereinafter" ancL are pivota'fly secumed 'te, avdum men pivot H. v

It is apparent from the that thfrotair tion of the zand. ofthe cam;lyrigicl therewithsha sa for 'itsgact ion to-make the" twolevers 8;air-@193 rock mundthepivot -H so -as toprovide the rising and" sinkingmovement; f; thegpistonsvi anhzi; 2". The outline of the am 'le isdefined im'the example illustrated in. a -mannensueh as winiqamsince,for each revolution a 'su'ction 'stroke. and a; delivery stroke foreachipistonm To ensure "a regmztr oixtput; the-butlinept the cam isdesigned sotas twensure' a; "ifispl'aeerrient o'fithe pistonsiwhiohisrbpdrtfonai to the single oiifotation oi the sh'a ft takmg intoihcoount'the corrections which it is necessiairy to-bflng thereto ion the reasonsdisclosed hereinafter;

The; pump dilustregted is= designedzs'oaas to ailIOW the operation. of'thee'csimta nd do nperating memai end thebsha-ftti rotates ans-mean outshaft. However, with the: monn'ti "ii I 6 (588,797

Wall is subetantimi u shapeit tress;- setiont Fennelwali's I ai'a'd noerase the id'bfi the casing me lower face at aura-a totn'e pump body vtwec nnaers. Insinethisban-1- are the 1 itstwobearings Ht, the tweronere and B ronin over the" the three-be i ings of the rocking levefs aommonpivot 1-? l bent p ge of the were 9 tine-t 9 mehtionee-pi'ece'o n gl"has been prov ifed so to a/HOW s 1. Ievers to pr-meet above the we g1-2- the open g; of which is reduced to a: while M1wme the pivot H! toJoe immersed A fluid-tight packing l5 is'h'i r iaIng e let of thec'ainsharft. T0 I iSne eteetinn of the drawing-member and of the on any:extraneous: (inject the uppee par 6f the eas mg is entirely mosed by apiote' mg encloisin gfluid-ti htly an the membei s etmti'o'k ling the;pump.

Inorder to protect the sum mechanism against *projebt' from between thepiston and-the Walt the yfihcieh, ehiefiy ihthe ease ofi wean iai-i'y oiquidthe direction of the axisof" the minder-errethroug h which thepiston rods are eaaptea to slide. iel'dthg fluid-ti ht arran ement a maymore o t/er provided between seiarmssana' t'nenooas I:

It'hais ween stated that the oathnept is iieei'gned so iis to enmeatpumpautputwmen is pmpdrtionai the angle e f ratiati'on of "e twodead.poims ai pear ge'spectively the; exitsidesaiid inside of each icfllia 'r alling two 'di'fier'e'nii diameters X; Y forming onewanother "anangle-21. 'cons'equentlynssthe dam: issupposed, torot'ate i n thectfrection oftl i'e arrow; the passage;

from me outerneaci point drone f the -i'bl lrsQ,

w dribbsffte direction eorresponds to ISU -Pai. e. the delivery-strokeax me ts the pistons 2 corresponds atothation ti irfiugh of the lpistonis at, every moment pmpoiibibhfl to 'theoiinpiittuietof the-rotationofi' the eam, wife bath against,-

cylinders will feed the same amount of liquid during periods ofdifferent durations.

In order to remove this drawback it is possible to correct thedifierence in the speed of operation of the pistons 2 and 2' through adlfierence reversely proportional thereto of the corresponding cylindervolumes; this may be obtained either as illustrated in Fig. 1 by adifference in the crosssection of the cylinders-l and l or. else by adifference in the strokeo'f the pistons obtained through a difference inlength of the lever arms or else by a combination of these two means.

According to my invention, there exists between the two balance beams orlevers 9-9 a connection which may be broken and which is such that therocking of one of the levers in the delivery direction round itspivoting axis produces a rockdirection of suction or reversely. The camhaving a constant diameter, it is not necessary in theory to provide aspring for urging the balance beams or levers into contact with it. Thedisconnection may then be ensured by breaking the connection or more.precisely by transforming their mutual operative connection into a rigidconnection whereby the two 'balance beams are set in a position ofmaximum opening outside the field of action of the cams.

In the form illustrated in Figs. 3 and 4 said conne-ction' is' ensuredthrough a semi-circular link l9 secured to the two levers 9 and 9' at 20and 20' respectively, said link cooperating with a roller 2p|=carried bya lever 22 which is adapted to rock around a stationary pivot 23 so asto raise andlower said roller. V

When said roller occupies the position shown in Fig. 3 for which thelink I9 is centrally located with reference to the rocking pivot ll,said link transmits from one balance beam or lever to the other therocking motion round said pivot I and the two rollers 8 and 8 constantlyfollow the outline of the cam. On the contrary when the roller 2| islowered as in Fig. 4 this results in a low-' ering of the semi-circularlink l9 and in bringing the levers 9 and 9' into a position which issymmetrically opposed for the two levers and outside the field of actionof the cam. The two balance beams remain rigidly held in their spacedposition until the roller 2| is'raised and again set in its centralposition with reference to the pivot If.

It will be noticed that the disengagement is operated without any effortof the cam but by a mere lowering of the roller 2|; the engagement maybe controlled from a distance through a sheathed cable for instance.

In practice, however, it is necessary to take into account theirregularities in the machinery and the wear of the cam and to providefora certain elasticity in the connection between the two levers. In thecase where, as illustrated, the roller 2| is controlled by a lever 22rocking'round a stationary point 23, said elasticity is ensured by meansof a spring 24 inserted in the control cable 25 engaging a, stationarylug 26. But it is still simpler .touse an arcuate link l9 made of springsteel which urges constantly towards one another the pivots 29 and 29(through which it is secured. to the levers) i. e. in the direction ofthe arrow F. Consequently the beams will have a tendency to move ingthedirection of the arrow F-.| and. to urge the rollers against the cam forthe connecting position of Fig. 3 in which a line through the pivots29-49 passesabove the axis of pivot On the contrary in Fig. 4 where'theline through pivots. 29-20- passes below th'e'axis of pivot l therollers move in the direction of the arrow F2 so as to be held outsidethe field of action of the cam.

As apparent the above described piston pump assumes a general shapewhich is substantially circular and is particularly well suited for themounting end to end of the driving shafts and even for the housing ofthe entire pump inside the rim ofa pneumatic tire. In the drawing I haveshown at 27 the rim of the wheel and at 28 its solid disc. The shaft 5of said pump is then in one with the shaft of the wheel 21-28 while thestationary casing of the pump is carried by an arm 29 rigid with theframe of the vehicle.

' What I claim is:

1. A pump comprising a rotary driving shaft,

' pump cylinders, pistons adapted to reciprocate ing of the otherthrough the same amount in the therein, levers controlling the pistons,a common pivot for the piston control levers, rollers carried at theouter ends of the levers, a cam mounted on the driving shaft and adaptedto control the angular position of said levers through said rollers,means for constantly urging said rollers against the cam elastically, avalve box between the cylinders.

2. A pump comprising a rotary driving shaft, pump cylinders, pistonsadapted to reciprocate therein, levers controlling the pistons, a.common pivot for the piston control levers a cam mounted on the drivingshaft and adapted to control the angular position of said levers, avalve box between the cylinders and a, container filled with oil insidewhich the levers and driving shaft are immersed, the levers being bentto an extent such r as will allow the-common pivot to be immersed in theoil bath inside the container, the lever arms on the piston sideextending out of the oil container.

3. A pump comprising a rotary driving shaft, pump cylinders, pistonsadapted to reciprocate therein, levers controlling the pistons, acommonpivot for the piston driving levers, rollers carried at. the outer endsofthe levers, a cam mounted on the driving shaft and adapted to controlthe angular. position of said levers through said rollers, means for.constantly urging said rollers against the cam elastically, a valve boxbetween the cylinders, the inner and outer dead points of the rollerslying on a line to one side of the axis of theshaft, and the cylindervolume. displaced by thepistons differing from one piston to the otherfor compensating the result of the unequal operation of the levers.

4. A pump comprising a rotary driving shaft, pump cylinders, pistonsadapted to reciprocate therein, levers controlling the pistons, a commonpivot forthe piston control levers, rollers carried at the outer ends'.of the levers, a cam mounted on the driving shaft and adapted tocontrol the angular position of said levers through said rollers, meansfor inter-engaging the levers and urging'them to either side of the camand means for controlling the. position of said last means fordisengaging as desired the levers and rollers thereon with reference tothe cam, and a valve box between the cylinders.

5. A pump comprising a rotary driving shaft, pump cylinders, pistonsadapted to reciprocate therein, levers controlling the pistons, a commonpivot for the piston control. levers, rollers carried at the outer endsof the levers, a cam mounted on the driving shaft and adapted to controlthe angular position of said levers through said rollers an arcuate'link 'pivotally secured to each lever through the corresponding end,means for making said link move between a central position withreference to the pivot between the levers for which the levers are inco-operating position with reference to the cam and an eccentricposition for which the levers are moved away from said cam, a valve boxbetween the cylinders.

6. A pump comprising a rotary driving shaft, pump cylinders, pistonsadapted to reciprocate therein, levers controlling the pistons, a commonpivot for the piston control levers, rollers carried at the outer endsof the levers, a cam mounted on the driving shaft and adapted to controlthe angular position of said levers through said rollers, a resilientarcuate link pivotally secured atgits ends to said levers, means formoving said link between a central position and an eccentricpositionwith reference to said common pivot, said levers cooperating with saidcam in said central position of the link, and said levers being" ininoperative relation to said cam in said eccentric position of the link,the elasticity of said link urging towards one another its points ofconnection with the levers and urging said levers into their operativeor inoperative position accordingto the position assumed by saidlink-moving means, a valve box between the cylinders.

7. -A pump comprising a rotary driving shaft, pump cylinders, pistonsadapted to reciprocate thereirrlevers controlling the pistons, a commonpivot for the piston control levers, rollers carried atfthe outer endsof the levers, a cam "mounted .on the driving shaft and adapted tocontrol the angular position of said levers through each lever throughits corresponding end, a roller engaging said link, and means forcontrolling the positionof said roller with reference to said commonlever pivot between the levers and thereby theoperativeness of thelevers with reference to thecafn, a valve box between the cylinders anda casing enclosing the different above-mentioned elements.

8. In combination with a vehicle wheel, a wheel shaft, a support, a pumpcomprising pump cylinders, pistons adapted to reciprocate therein,leversjjcontrolling the pistons, a common pivot for'the piston controllevers, rollers carried at the'outer ends of the levers, a cam mountedon thelwheel shaft and adapted to operate said levers means, for movingsaid link between a central position and an eccentric position withreference to said common pivot, said levers cooperating with said cam insaid central position of the link, and said levers being in inoperativerelation to said cam in'said eccentric position of the link, a valve boxlocated between said cylinders, and a casing enclosing the cylinders,pistons, and valve box secured to said support.

9. A pump comprising av rotary driving shaft, pump cylinders, pistonsadapted to reciprocate thereirii' valve means connected with saidcylinders, levers controlling said pistons, a common pivot for thepiston control levers, a cam mounted on the drivingshaft and adapted tocontrol the angular position of said levers, resilient means forconstantly urging said levers toward said cam, the angular travel ofsaid cam on the delivery stroke of one piston being greater than itsangular travel on the delivery stroke of the other piston, and the areasof said cylinders and strokes of said pistons being constructed andarranged to compensate for said unequal travel and to equalize deliveryfrom said pumps.

10; A pump comprising a rotary driving shaft, pump cylinders, pistonsadapted to reciprocate therein, valve means connected with saidcylinders, levers controlling said pistons, a common pivot for thepiston control levers, a cam mounted on the driving shaft and adapted tocontrol the angular position of said levers, means interengaging saidlevers and urging them oppositely toward the sides of the cam, and meansfor controlling the position of said interengaging means for moving asdesired the levers into or out of operative relationship to the cam.

11. =A pump comprising a rotary driving shaft, pump cylinders, pistonsreciprocating therein, levers controlling the pistons, a-common pivotfor the piston control levers located within the compass cream leversand their connections to said pistons, a cam mounted on the drivingshaft and adapted to control the angular position of the levers,resilient means for constantly urging said levers toward said cam, andalvalve box located between said cylinders and associated therewith.

12. Pump structure as claimed in claim 11 having a container filled withoil within which said levers and common shaft and driving shaft areimmersed with portions of said levers extending out of said both.

"13. A pump comprising a rotary driving shaft,

pump cylinders, pistons adapted to reciprocate therein, piston rods andlevers associated with said shaft and pistons, a valve box locatedbetween the cylinders forming with said cylinders and the rods of saidpistons a U-shaped whole, and means for the conversion of the rotarymovement into reciprocating movement, said converting 'means beingdisposed between the two branches of said U, and a casing comprising twolateral parallel walls and a lower Wall to which are secured thecylinders and the valve box, a container filed with oil inside saidcasing and within which said levers and driving shaft are immersed.

f 14. A pump as claimedin claim 13 having a cover adapted to cap thecasing .for protecting the piston rods, levers, shaft and containeragainst any detrimental outer action.

'15. A pump as claimed in claim 14 having an auxiliary hood capping thecylinders for preventing any projection of the liquid out of thecylinders.

. EMILE BOBARD.

REFERENCES CITED The following references are of record in the 1 fil-e.of this patent:

UNITED STATES PATENTS Number Name Date 798,506 Hall Aug. 29, 19051,382,450 Baker June 21, 1921 2,240,371 Linch et al Apr. 29, 19412,317,636 Parker Apr. 2'7, 1943 2,319,718 Brooks May 18, 1943 2,369,694Trippensee Feb. 20, 1945

